Ethylene polymers, i.e., homopolymers and copolymers, are easily molded or extruded into shaped articles. Additives are frequently used to improve the strength of the polymers. Efforts have also been made to improve the flame and smoke resistance of such polymers by adding various flame and smoke retardants. However, many such retardants have a negative effect on mechanical properties, such as strength properties, and it is desirable to discover combinations of strength-enhancing additives and flame and smoke retardants that provide a good balance between strength properties and flame and smoke retardancy. This invention is directed to such combinations.